This invention relates generally to an apparatus and method for extricating an immobilized rubber tired vehicle and, in particular, to a winching and traction intensifying apparatus and method which utilizes the weight of the vehicle exerted upon the non-driving tires to provide an anchor point for the winching action and includes a novel traction intensifying portion which fits the outer contour of and is rolled up upon the driving tires.
Various types of winching devices have been employed to enable an immobilized vehicle to extricate itself. Traditionally, they have been either permanently mounted and electrically driven by power furnished by the vehicle engine, or they have been temporarily mounted and secured to the hubs of the driving wheels by winching drums. Devices of both types are not only cumbersome and expensive, but also depend upon some foreign fixed object to provide the necessary anchor point for the winching action.
Numerous approaches have been taken to improve upon vehicle traction characteristics while negotiating adverse ground conditions. For example, one well known approach is the so-called "snow tire". Snow tires have a tread configuration consisting of deep grooves located between protruding ribs for extra gripping action. However, this configuration is frequently inadequate since, in order to provide a reasonably smooth ride, the protrusions must be located at the sides of the tire tread where very little of the vehicle's weight is exerted upon the ground surface.
A second approach to the problem has been to insert numerous studs in the tire itself and has been used in combination with the snow tire concept discussed earlier. These studs protrude from the center portion of the tread itself and are generally regarded as an effective means of improving traction. However, since the studs are normally fashioned from a hard, wear resistant material such as hardened steel, they tend to damage paved roadways, and, in fact, are prohibited by law in many locations.
Snow chains have also become widely accepted as a traction intensifying device; although they are becoming increasingly unpopular because they are expensive, cumbersome to install and remove, and noisy in operation.
The present invention overcomes these and other problems associated with prior art vehicle extricating systems and traction intensifying devices by employing a relatively easily installed winching device which eliminates the need for a foreign fixed point by using the vehicle weight itself, as transmitted through the non-driving tires to the supporting surface, to provide an anchor.
Simultaneously, while an immobilized vehicle is winching itself out of its predicament, a resilient, non-metallic traction intensifying means conforming to the outer contour of the driving tires is rolled up tightly about the circumference of the driving tires thereby giving them superior traction characteristics.